While heartburn medication can be a lifesaver for those suffering from gastric reflux, several studies over the years have indicated that the drugs could increase stomach cancer risks more than threefold. A new meta analysis says that's likely not the case.
Proton pump inhibitors (PPIs) are a class of drugs that work by blocking an enzyme that produces stomach acid. They include such popular medications as Nexium, Prevacid, and Prilosec, and they can turn down the burn often felt by people suffering from peptic ulcers as well as gastroesophageal reflux disease (GERD).
But in addition to providing relief to patients, some research has said these drugs may have a darker side as well. They have, for example, been linked to the development of dementia, and several studies in the last few years have said they can be a factor in the development of stomach cancer. One meta-analysis even linked the use of PPIs to an approximate three-time increase in stomach-cancer rates.
Researchers from Scandinavia, Iceland, Finland and the UK decided to take one more look at the research linking PPI use and cancer and found enough evidence to make them think it was all standing on some pretty shaky ground. So they decided to conduct their own analysis.
To do so, the team looked at healthcare registry data from Denmark, Finland, Iceland, Sweden, and Norway over the 26-year period from 1994 to 2020, and found 17,232 people who had developed stomach cancer. The researchers put each of those individuals into a group with 10 other healthy people from their respective countries, matching up age, sex, and calendar year. That gave them a total pool of 172,297 people to examine.
Crucially, in their analysis, the researchers excluded the use of PPIs in one year before stomach cancer diagnoses. That's because stomach cancer symptoms can often show up as pain, reflux and indigestion, so doctors will prescribe the medicine as a way to treat those symptoms before even realizing that a patient has stomach cancer. So in other words, it is often the case that stomach cancer patients are put on PPIs because of their symptoms rather than developing cancer as a result of taking PPIs.
When all of that was taken into account, any association between use of the drugs and development of stomach cancer disappeared. The authors argue that the earlier studies showing the link were inconsistent, and limited by confounding and methodological differences, making it hard to draw firm conclusions about cancer risk.
Still, the researchers caution that even their current analysis is an observational study from which definitive cause-and-effect conclusions cannot be drawn. However they feel the sheer amount of data fathered and the lengthy timeframe they analyzed lends their work credence.
"The results of this study do not support the hypothesis that long term proton pump inhibitor use is associated with an increased risk of gastric adenocarcinoma," they say. "This finding should offer relief for patients needing long term proton pump inhibitor therapy and is valuable for healthcare in clinical decision making."
That's important because long-term untreated gastric reflux can lead to serious complications including cancer of the esophagus. So patients who avoid PPIs based on previous studies that may have been faulty are likely not making the best decision for their long-term health.
The study has been published in The BMJ.
Source: BMJ Group via EurekAlert
